If you find something with thunderbolt, you can get an external controller in there via thunderbolt->pcie. But between that power draw, and the draw of the driv

If you find something with thunderbolt, you can get an external controller in there via thunderbolt->pcie. But between that power draw, and the draw of the drives, you'll be bumping close enough to 40w that it'd be a wash. I do this math myself every few months and ultimately, it seems for a large nas/server, 40-50W is about as low as you can idle.